3. Abi. Leah and Savannah decide to have a 3-rope tug-of-war by pulling horizontally in different directions. Abi pulls with a force of 50 N [N], while Savannah pulls with a force of 45 N [E 55' S]. Astoundingly, when Leah pulls on her rope, all three of the combatants find themselves motionless. What is the magnitude and direction of the force that Leah has to exert for this to be true? (Answer: 29 N [W 26.9' S]) 4. (p. 169 - #24, Frames of Reference) An 18 g rubber stopper is suspended by a 45 cm string from the rear-view mirror of a car. As the car accelerates eastward, the string makes an angle of 5.10 with the vertical. (a) Draw a force diagram of the stopper in the Earth's frame of reference. (b) Write net force equations and use them to determine the acceleration of the car. (Answer: 0.87 m/s?) 5. Slade wakes up one morning, and gets up out of bed, feeling lighter than usual. He steps onto a conveniently placed bathroom scale that he never knew he owned, and notices that the scale reading is just half of what it normally reads. As he peers out the window, he notices that the entire house is moving. Draw a force diagram and write net force equations to help Slade determine the acceleration (magnitude and direction) of his house. (Answer: 4.9 m/s', downwards)